添加饲料枣、大豆皮或鲜啤酒渣对奶牛产奶性能的影响

将40头荷斯坦奶牛随机分为4个试验组,每组10头奶牛。试验1组的日粮为13.9%粗蛋白质(CP)、产奶净能(NEL)7.23 MJ/kg和0.58%赖氨酸(Lys),添加饲料枣、大豆皮或新鲜啤酒渣,试验2组～4组为CP13.9%、NEL 7.02 MJ/kg和依次0.54%、0.52%0、.52%Lys。所有试验奶牛先饲喂10 d试验日粮作为预试期,然后开始70 d正试期。试验4组产奶量平均为(27.75±1.31)kg/d,略高于试验1组[(27.20±0.69)kg/d]和试验3组[(27.25±0.87)kg/d](P0.05);试验2组产奶量略有下降[(26.65±0.64)kg/d],但差异不显著(P0.05)。因此,日粮CP水平保持在13.9%条件下,适当降低日粮赖氨酸含量,饲料枣和新鲜啤酒渣的快速降解非纤维碳水合化物和瘤胃降解蛋白质弥补了日粮中Lys含量的不足,产生氨基酸节省效应(amino acid-spare effect),有助于提高产奶量,增加产奶纯收入。分别添加饲料枣、新鲜啤酒渣和混合添加饲料枣、大豆皮、新鲜啤酒渣的低成本日粮有利于提高奶牛产奶量、乳成分和经济效益。     

旱养模式黑番鸭0～21d能量与粗蛋白需要的研究

研究以旱养模式黑番鸭为素材,通过饲养试验和代谢试验结合,运用综合法和析因法研究了日粮不同代谢能和粗蛋白梯度水平对育雏期(0~21 d)生长性能的影响及该阶段日粮代谢能和粗蛋白的需要量。每个试验阶段均采用3×2因子试验设计,育雏期选用体重(50.81±1.33)g差异不显著(P0.05)的0日龄黑番鸭苗3 000羽,随机分为6个处理组,每个处理5个重复,每个重复100羽;日粮代谢能水平分别为11.50、12.10、12.70 MJ/kg,粗蛋白水平分别为19%、20%。结果表明:日粮ME12.70 MJ/kg、CP 20%组日增重最高,采食量、料肉比最低,钱肉比低,生产效果好,经济效益高。得出旱养模式黑番鸭(0~21 d)日粮代谢能及粗蛋白质需要:ME(kJ/d)=244.15BW~(0.75)+22.60△W,CP(g/d)=1.53BW~(0.75)+0.29△W,该阶段日粮ME和CP适宜水平为12.09 MJ/kg、19.48%。     

不同豆粕添加量的日粮对奶牛产奶性能的影响

将40头荷斯坦产奶牛随机分为4个试验组,每组10头。4种试验日粮均配制成蛋白质(CP)含量15.2%、产奶净能(NEL)6.90~7.06 MJ/kg。日粮通过调节豆粕和棉籽粕的用量改变日粮赖氨酸(Lys)含量,这样试验1组日粮赖氨酸含量为0.65%、试验2组0.62%、试验3组0.59%和试验4组0.56%。所有试验奶牛先饲喂10 d试验日粮作为预试期,然后开始70 d正试期。试验1组产奶量最高,平均为(27.13±1.53)kg/d;试验4组产奶量最低,平均为(24.40±1.56)kg/d;试验2组和3组依次为(26.18±1.37)和(25.27±1.58)kg/d;其中试验1组产奶量明显高于试验3组(P<0.01)和试验4组(P<0.01),试验2组明显高于试验4组(P<0.05)。因此,在日粮蛋白质含量保持相同和产奶净能相近的条件下,提高日粮赖氨酸含量则提高了奶牛产奶量,降低日粮赖氨酸含量则降低了奶牛产奶量;大量使用棉籽粕替代豆粕降低日粮赖氨酸含量,导致产奶量降低;尽管日粮赖氨酸含量容易提高奶牛日粮成本,由于提高产奶量,增加了产奶纯收入。使用日粮赖氨酸含量这一指标有利于评价奶牛产奶量、乳成分和经济效益。     

基于饲养标准的家畜单位折算方法

为解决载畜量核定工作中存在的家畜单位折算体系不健全、与畜牧业统计口径脱节等问题,根据肉牛单位、绵羊单位的定义和肉牛、肉羊、奶牛饲养标准中的代谢能或净能需求以及标准干草的代谢能或净能含量,研究确定肉牛单位、绵羊单位和不同生理阶段奶牛的标准干草需求及其家畜单位折算关系.结果表明:标准干草代谢能或净能含量分别为肉牛综合净能4.89 MJ/kg,奶牛产奶净能5.57 MJ/kg,绵羊代谢能8.68 MJ/kg;1个肉牛单位、绵羊单位的能量需求分别是肉牛单位72.10 MJ/d综合净能、绵羊单位18.46 MJ/d代谢能,其家畜单位折算关系是6.93∶1;不同生理阶段奶牛的平均产奶净能需求分别是断奶犊牛27.19 MJ/d、育成母牛52.07 MJ/d、初孕母牛70.11 MJ/d和中产泌乳母牛123.95 MJ/d,折合标准干草需要量分别为4.88 kg/d、9.35 kg/d、12.59 kg/d和22.25 kg/d,分别折合2.29、4.39、5.91和10.45个绵羊单位;生产上一般按照奶料比3.5∶1补充精饲料,则中产泌乳母牛对标准干草的平均需要量调整为15.06 kg/d;从天然草地的放牧压力和区域粗饲料的供需状况评价的角度,建议中产泌乳母牛与绵羊单位的折算系数由10.45调整为7.07.     

生长前期丝羽乌骨鸡饲粮适宜能量、蛋白水平研究

两因子设计 ,以1日龄丝羽乌骨鸡504只为材料 ,进行饲养试验结合代谢试验考察了饲粮代谢能(ME)、粗蛋白质(CP)对生长前期(0～8周)丝羽乌骨鸡生产性能的影响规律。结果表明 ,通过饲粮营养调控可显著改善生长前期丝羽乌骨鸡的生长速度和生产性能 ,ME显著(P<0.05)或极显著(P<0.01)影响各阶段平均日采食量(ADFI)和饲料转化率(FCR) ,CP显著影响3周龄前的生产性能指标(P<0.05) ,二者互作影响不显著(P>0.05) ;增加营养素摄入量有利于改善丝羽乌骨鸡对营养素的表观利用率。推荐3周龄前饲粮ME为13.40MJ/kg、CP为20 % ,整个生长前期(0～8周)推荐使用ME为12.35MJ/kg、CP为18 %饲粮以获得较好生产成绩和经济效益     

岭南黄肉鸡前期日粮适宜蛋白质和能量水平的研究

试验旨在研究岭南黄肉鸡前期 (0～ 4周 )日粮适宜的蛋白质 (CP)和能量水平 (ME)。采用二因子试验 ,设计 4 (CP)× 4 (ME)共 16个处理。每处理三个重复 ,每重复 16只母雏。蛋白质水平分别为 18%、19 5 %、2 1%、2 2 5 % ,代谢能 (ME)水平分别为 11 3、11 9、12 5、13 1MJ/kg。结果表明 ,综合考虑增重和饲料报酬两个指标 ,岭南黄鸡生长前期 (0～ 4周 )日粮适宜的CP和ME水平分别为 2 1 0 %和12 5MJ/kg。     

日粮代谢能水平对“京粉1号”蛋鸡产蛋高峰期生产性能的影响

为研究日粮代谢能(ME)水平对“京粉1号”商品代蛋鸡产蛋高峰期生产性能的影响,试验选用32周龄“京粉1号”商品代蛋鸡360只,随机分为4组,每组9个重复,每个重复10只鸡,日粮ME分别为10.76、10.86、11.04、11.26 MJ/kg。预试期2周,正试期10周。结果表明:日粮ME水平对蛋鸡产蛋高峰期的平均日采食量具有极显著影响(P<0.01),当ME水平大于10.86 MJ/kg时,平均日采食量随ME水平升高呈线性下降;10.86 MJ/kg ME组的平均日增重极显著高于11.26MJ/kg组(P<0.01),对试鸡ME日摄入量与日增重进行回归分析得出最佳ME日摄入量为1.163MJ/d;日粮代谢能水平对产蛋率、平均蛋重、日产蛋量、破损蛋率、料蛋比等生产性能无显著性影响;各组间养分表观代谢率差异不显著。综合生产性能指标,“京粉1号”商品代蛋鸡产蛋高峰期日粮中适宜的ME水平为11.04MJ/kg,适宜的ME日摄入量为1.163MJ/d。     

5～10周龄织金白鹅能量和粗蛋白需要量的研究

试验选用健康、体重基本一致29日龄织金白鹅270只,采用3×3因子正交试验设计,试验鹅随机分为9组,分别饲喂不同能量和粗蛋白水平日粮(共9组),代谢能(ME)水平分别为10.53、11.72 MJ/kg和13.20 MJ/kg,粗蛋白(CP)为14.0%、15.5%和17.0%。结果表明,5~10周龄织金白鹅能量和蛋白质的需要量分别为ME=579.47BW~(0.75)+45.76△W,CP=2.43BW~(0.75)+0.52△W。该阶段织金白鹅的能量(ME)和粗蛋白(CP)维持需要分别是:579.47 k J/BW~(0.75)和2.43 g/BW~(0.75),该阶段日粮中ME和CP适宜需要量分别为11.71 MJ/kg和15.18%。     

1～4周龄织金白鹅能量和粗蛋白需要量研究

试验采用3×3因子正交试验设计,将270只1日龄织金白鹅随机分为9组,分别饲喂不同能量和粗蛋白水平日粮,代谢能(ME)水平分别为10.34、11.49和12.64 MJ/kg,粗蛋白(CP)水平分别为18%、20%和22%。结果表明:1~4周龄织金白鹅能量和蛋白质的需要量分别为ME=392.36BW~(~(0.75))+32.693ΔW和CP=1.69BW~(0.75)+0.4833ΔW;该阶段织金白鹅的能量(ME)和粗蛋白(CP)维持需要分别为392.49.KJ/W~(0.75)和1.75g/W~(0.75);日粮中ME和CP适宜需要量分别为11.29 MJ/kg和19.91%。     

饲粮代谢能水平对1～3周龄四川白鹅生长性能和血清生化指标的影响

本试验旨在研究饲粮代谢能(ME)水平对1~3周龄四川白鹅生长性能和血清生化指标的影响。选择780只体重相近、健康的3日龄四川白鹅,随机分成5组,每组6个重复,每个重复26只。采用单因素试验设计,设5个饲粮ME水平:12.86、12.13、11.43、10.73和10.00 MJ/kg,饲粮粗蛋白质水平均为20%。试验期为18 d。结果表明:1)饲粮ME水平10.00 MJ/kg组平均日采食量和料重比极显著高于其他各组(P0.01),饲粮ME水平12.13和10.00 MJ/kg组末重、平均日增重均显著高于饲粮ME水平10.73 MJ/kg组(P0.05)。2)饲粮ME水平12.86 MJ/kg组的饲料成本最高,饲粮ME水平10.73 MJ/kg组的饲料成本最低。3)饲粮ME水平12.86 MJ/kg组血清总胆固醇含量显著或极显著低于其他各组(P0.05或P0.01),饲粮ME水平10.73、10.00 MJ/kg组血清低密度脂蛋白含量极显著低于其他各组(P0.01),饲粮ME水平12.86 MJ/kg组血清谷草转氨酶、碱性磷酸酶活性均极显著高于其他各组(P0.01)。回归分析表明,以低料重比、高平均日增重为衡量指标,推荐1~3周龄四川白鹅饲粮ME水平为12.22 MJ/kg;以高平均日增重、低饲料成本为衡量指标,推荐饲粮ME水平为10.75 MJ/kg。     

饲用甜菜块根混贮饲喂荷斯坦牛的试验研究

采用75%切碎的饲用甜菜根茎与15%芦苇草粉、8%棉籽壳及2%玉米粉进行混合青贮,并替代荷斯坦奶牛常规日粮中的部分玉米青贮,进行饲喂对比试验。结果表明,饲用甜菜混贮饲料干物质含量为27.8%、粗蛋白含量为2.76%、粗脂肪含量为0.92%、粗纤维含量为11.28%、粗灰分含量为3.23%、钙含量为0.10%和磷含量为0.04%。饲用甜菜混贮饲料等量替代10kg奶牛日粮中的玉米青贮饲喂奶牛,试验组比对照组每头奶牛日平均产奶量降低0.09kg,试验末期对照组和试验组的乳蛋白率分别为3.17%和3.18%,乳脂率分别为3.66%和3.73%,分析结果表明,产奶量及乳品质差异均不显著。可见饲用甜菜块根混贮是一种较好的饲料,可以替代玉米青贮饲喂奶牛,混贮是饲用甜菜块根一种理想的贮藏方法。     

苜蓿干草不同添加量对奶牛产奶量和乳脂率的影响

选择年龄、体重、胎次、生理状况、泌乳天数等相近的经产奶牛(泌乳中期的荷斯坦奶牛)16头,随机分为4组(对照组A、试验组B、C、D),每组4头,试验预试期10 d,正试期30 d。测定奶牛产奶量和乳脂率。试验组B、C、D组的日粮配制是在对照组的基础上,分别添加3.5 kg、6.5 kg、9.5 kg的苜蓿干草替代部分精料。试验结果表明:试验B、C和D组与对照组相比,平均产奶量分别提高1.1kg、2.58 kg和1.58 kg,分别提高了4.18%、9.72%和5.95%,试验组与对照组差异显著(P0.05),各试验组间C与B、D差异显著(P0.05)。经济效益分别提高6.41%、13.92%、5.13%。     

A semi-parametric model for lactation curves: development and application

We propose a semi-parametric model for lactation curves that, along with stage of lactation, accounts for day of the year at milk recording and stage of gestation. Lactation is described as having 3 different phases defined by 2 change points of which the second is a function of gestation stage. Season of milk recording is modelled using cosine and sine functions. As an application, the model is used to estimate the association between intramammary infections (IMI) dynamics as measured by somatic cell count (SCC) over the dry period and the shape of the lactation curve. Milk recording data collected in 2128 herds from England and Wales between 2004 and 2007 were used in the analysis. From a random sample of 1000 of these herds, smoothed milk production was used to test the behaviour of the model and estimate model parameters. The first change point was set at 60 days in milk. The second change point was set at 100 days of gestation or 200 days in milk when the latter was not available. Using data from the 1128 remaining herds, multilevel models were then used to model individual test-day milk production within lactations within herds. Average milk production at 60 days in milk for cows of parities 1, 2, 3 and greater than 3 were 26.9 kg, 31.6 kg, 34.4 kg and 34.7 kg respectively and, after this stage, decreases in milk production per 100 days milk of lactation were 3.1 kg, 5.1 kg, 6.3 kg and 6.7 kg respectively. Compared to cows that had an SCC below 200,000 cells/mL on both the last milk recording in a lactation and the first milk recording in the following lactation, cows that had an SCC greater than 200,000 cells/mL on their first milk recording after calving had an estimated loss of milk production of between 216 and 518 kg depending on parity. These estimates demonstrate the impact of the dynamics of SCC during the dry period on milk production during the following lactation.     

微生态制剂对奶牛产奶量和乳品质与肠道菌群的影响

通过在奶牛饲粮中添加微生态制剂,研究其对奶牛产奶量、乳品质和肠道菌群的影响。试验从200头成年产奶牛中,选取20头年龄、胎次、泌乳月份、妊娠期、产奶量、体重基本相似且身体健康的荷斯坦奶牛,分为试验组和对照组,试验期为35 d。其中对照组按照常规方式饲养,试验组在精料中按1‰的比例加入复合微生态制剂。结果表明:对照组奶牛平均产奶量降低,每头日均产奶量减少0.36 kg(P>0.05),而试验组每头日均产奶量比对照组增加1.81 kg,增产16.97%,差异极显著(P<0.01);与对照组相比,试验组蛋白质、乳糖和非脂乳固体增加,但差异不显著(P>0.05),脂肪降低(P<0.05);最后采用PCR-DGGE技术分析奶牛肠道菌群,结果试验组肠道菌群多样性明显高于对照组,且相似性达到97%,证实微生态制剂具有调节奶牛肠道菌群平衡的作用。     

岗岭地牧草栽培与利用

为探讨开发利用岗岭低产土地资源的有效途径,从1984—1989年在踢球山种畜场进行牧草栽培,一年生草地每公顷产鲜草平均85815公斤,多年生草地平均每公顷产鲜草49275公斤。每天每头奶牛饲喂15公斤鲜草以代替部分干草,每月比精料加粗料常规饲喂方法增奶量为34.6%,每公顷鲜草饲喂增值效益达6000元以上。     

意大利黑麦草饲喂奶牛效果

试验对采用冬闲水田生产的意大利黑麦草Lolium multiflorum饲养奶牛效果进行研究。通过23 d（5 d预试期+18 d正试期）的奶牛饲喂试验,发现采用部分或者全部黑麦草代替野生杂草作为奶牛的青饲料均能够不同程度地提高奶牛的日产奶量,延长奶牛的泌乳高峰期,并提高牛奶中蛋白质的含量,试验还证明了黑麦草提高牛奶乳蛋白率的作用在奶牛泌乳高峰期与下降阶段同样成立。通过经济效益估算,全部以黑麦草代替野生杂草作为奶牛青饲料,增收达到每天6.0元/头,经济效益显著。     

The virulence of L. leucocephala for goats in northeastern Mexico

When fed 100% Leucaena during a period of 45 days goats with experience in L.-fodder took significantly (P less than 0.05) more dry matter (50.01 g/kg0.75) than those without or only possible experience (44.40 g/kg0.75 and 45.63 g/kg0.75). The uptake of Mimosine from animals with Mimosine experience (1.14 g/kg0.75) has also been significantly higher (P less than 0.05) than from two other groups with non or only possible experience (0.93 g/kg0.75 and 0.92 g/kg0.75). The Serum-Thyroxin level (T4) of the control group (5.12 micrograms/100 ml) and of the group with Leucaena experience (4.65 micrograms/100 ml) has been significantly higher (P less than 0.05) during the entire trial period than that of the two other trial groups (3.9 micrograms/100 ml). Hair-loss, reduced fodder uptake, increased salivation, excitation, ataxia of hind legs, vomit of fodder and uncoordinated chewing of fodder have been observed in animals without or only possible Leucaena experience. Three animals of those died through direct or indirect influence of the poisoning. Swollen buccal papillae, ulceration and necrosis of the oesophagus and haemorrhagic lesions in the reticulum and rumen have been observed in two of the dead animals.     

Relation between 15N excretion in feces following oral 15N urea administration and blood urea concentration in relation to raw fiber intake in swine

9 pigs of a live weight at the beginning of the experiment of 33 kg received in 3 consecutive series of experiments (3 animals/group) a basic barley ration of 1.0-1.2 kg per animal and day. In groups 1 to 9 the following supplements were given: 1 = without N-supplement, 2 = 10.5 g urea, 3 = 79 g dried skim milk, 4 = 11 g urea, 5 = without N-supplement, 6 = 110 g horse bean coarse meal, 7 = without N-supplement, 8 = 95 g dried skim milk, 9 = 120 g horse bean coarse meal. In groups 1-6 the ration was supplemented with 150-165 g DM partly hydrolysed straw meal per animal and day. After 20 days the animals received a single dosis of 0.5 g/kg0.75 15N-urea (72.1 atom-% 15N-excess) with the morning meal of the first day of the experiment. During the four days of the experiment groups 1-6, due to the straw meal supplement, excreted significantly higher N-amounts than the corresponding groups 7-9. In comparison with the first day of the experiment (1 h after the morning meal) urea concentration in the blood decreased to the following percentage in the sequence 1-9: 64; 65; 77; 54; 64; 73; 82; 88; 84 on the second day of the experiment (1 h before the evening meal. Between the excretion of 15N-excess in faeces (y = mg) during the four days of the experiment and the concentration of urea in the blood (x = mmol/l) there was the following significant negative correlation: y = -40.1 X +340.(ABSTRACT TRUNCATED AT 250 WORDS)     

Calliandra calothyrsus as a Supplement for Milk Production in the Kenya Highlands

Two on-farm experiments and one on-station observation were conducted between July 1994 and September 1995 to study the effect of supplementation with fresh fodder of Calliandra calothyrsus on milk production from grade Friesian and Ayrshire cows in the second trimester of their lactations. The cattle were kept under zero-grazing systems on small farms in the coffee-based land use system at altitudes of 1500 to 1800 m on the slopes of Mt Kenya. These cows form a pivotal part of the farming system since they produce both milk for sale and manure for crop production. Milk production is normally in the region of 10 kg/cow per day when the animals are fed on a diet based on Napier grass and crop residues, together with 2–4 kg/day of commercial concentrate. In terms of milk production, 3 kg of fresh calliandra had the same effect on yield as 1 kg of additional dairy meal and, at normal production levels, the effects of the two supplements were strictly additive. Calliandra had a marked positive effect (about a 10% increase) on the butterfat content of the milk, a factor that was highly valued by farmers, even though institutional buyers as yet offer no premium price for milk quality. The average small farm can produce enough calliandra fodder to supplement two dairy cows and some additional small stock from relatively underutilized niches along the farm perimeter and terrace risers, without any adverse effect on current levels of crop production.     

Impact of feeding pattern and feed purchase on area- and cow-related dairy performance of organic farms

Livestock production and ruminants in particular are an integral part of the organic mixed farming concept. In this paper, the feeding patterns of 26 organic dairy farms in two different regions in Germany are analysed, with particular emphasis on the amount and proportion of concentrates and purchased feed related to the dairy performance expressed per cow and hectare. Calculated on an energy basis (MJ NEL), the annual average milk yield of 6737 kg cow^− 1 is derived from roughage (74%), concentrates and cobs (23%), and commercial processing by-products (e.g., spent grains) (3%). Per cow and year, 937 kg dry matter (DM) (range: 0–2724 kg) of concentrates are fed with an intensity of 135 g kg^− 1 milk (range: 0–378 g kg^− 1). Approximately 65% of the concentrates and commercial processing by-products are purchased. The area-related milk yield is almost 7000 kg ha^− 1. For fodder production, 0.96 ha per cow is needed, of which 0.85 ha is farm land. The equivalent production area for purchased fodder is 0.11 ha. In the analysed region in northwestern Germany, most correlations between milk yield and analysed feeding parameters are close and significant. This is in contrast to the region in the south, where the variability of amount and proportion of the different feed types is predominantly independent of the milk yield. Intensification of dairy production to increase milk performance using a higher proportion of concentrates and purchased feed at some of the analysed farms needs to be carefully assessed according to the organic farming profile.